Methods and apparatus for sclerosing the wall of a varicose vein

ABSTRACT

A preferred apparatus for delivering an intravascular drug such as a sclerosing agent (or a microfoam sclerosing agent) to a varicose vein includes a catheter having three concentric tubes. The innermost tube has a guide wire lumen and an inflation lumen. The distal end of the innermost tube has an integral inflatable occlusion balloon in fluid communication with the inflation lumen. The intermediate tube has a lumen through which the innermost tube extends. The distal end of the intermediate tube has a self-expanding balloon with a plurality of fluid pores in fluid communication with the intermediate tube lumen. The outer tube has a lumen through which the intermediate tube extends. Sclerosing agent is dispensed through the intermediate tube to pores located at the distal end of the intermediate tube or in the self-expanding balloon. Veins are sclerosed as the self-expanding balloon is pulled through and ultimately out of the vein.

[0001] This application claims the benefit of the following provisionalapplications: serial No. 60/219,931 filed Jul. 21, 2000; serial No.60/221,469 filed Jul. 26, 2000; serial No. 60/225,172 filed Aug. 14,2000 the complete disclosures of which are hereby incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The invention relates to the treatment and correction of venousinsufficiency or varicose veins. More particularly the invention relatesto a minimally invasive procedure using a catheter-based system tosclerose the wall of the vein.

[0004] 2. State of the Art

[0005] The human venous system of the lower limbs consists essentiallyof the superficial venous system and the deep venous system withperforating veins connecting the two systems. The superficial systemincludes the long or great saphenous vein and the short saphenous vein.The deep venous system includes the anterior and posterior tibial veinswhich unite to form the popliteal vein, which in turn becomes thefemoral vein when joined by the short saphenous vein.

[0006] The venous systems contain numerous one-way valves for directingblood flow back to the heart. Venous valves are usually bicuspid valves,with each cusp forming a sack or reservoir for blood which, underpressure, forces the free surfaces of the cusps together to preventretrograde flow of the blood and allow antegrade flow to the heart. Anincompetent valve is a valve which is unable to close because the cuspsdo not form a proper seal and retrograde flow of blood cannot bestopped.

[0007] Incompetence in the venous system can result from vein dilation.Separation of the cusps of the venous valve at the commissure may occuras a result. Two venous diseases which often involve vein dilation arevaricose veins and chronic venous insufficiency.

[0008] The varicose vein condition includes dilatation and tortuosity ofthe superficial veins of the lower limb, resulting in unsightlydiscoloration, pain and ulceration. Varicose veins often involveincompetence of one or more venous valves, which allow reflux of bloodfrom the deep venous system to the superficial venous system or refluxwithin the superficial system.

[0009] Varicose veins are compatible with long life and rarely causefatal complications, but the condition significantly decreases thequality of life. Patients complain primarily of leg fatigue, dull,aching pains, ankle swelling, and ulcerations. Occasionally, thrombosisoccurs in dilated subcutaneous channels, resulting in local pain,induration, edema, inflammation, and disability. In addition to thoseproblems, the high visibility of the unattractive rope-like swellingsand reddish skin blotches causes considerable distress for both men andwomen. Lastly, varicose eczema, which is a local reddened swollen anditching skin condition can occur and can spread to distant parts of thebody (called an “Id reaction”).

[0010] Phlebosclerosis, the destruction of venous channels by theinjection of sclerosing agents, has been used to treat varicose veinssince 1853, when Cassaignae and Ebout used ferric chloride. Sodiumsalicylate, quinine, urea, and sodium chloride have also been used, butthe agent more recently favored is sodium tetradecyl sulfate. In orderfor phlebosclerosis to be effective, it is necessary to evenly dispensethe sclerosing agent throughout the wall of the vein without using toxiclevels of the sclerosing agent. This is not particularly difficult forthe smaller veins. However, it is quite difficult or nearly impossiblein larger veins. When a larger vein is injected with a sclerosing agent,the sclerosing agent is quickly diluted by the substantially largervolume of blood which is not present in smaller veins. The result isthat the vein is sclerosed (injured) only in the vicinity of theinjection. If the procedure is continued, and the injections are farapart, the vein often assumes a configuration resembling sausage links.The problem cannot be cured by injecting a more potent solution ofsclerosing agent, because the sclerosing agent may become toxic at sucha concentration.

[0011] U.S. Pat. No. 5,676,962 discloses an injectable microfoamcontaining a sclerosing agent. The microfoam is injected into a veinwhere it expands and, theoretically, achieves the same results as alarger quantity of sclerosing agent without the toxicity. Such a foam ispresently manufactured under the trademark Varisolve® by Provensis,Ltd., London, England. Recent clinical trials of the foam indicate asuccess rate of 81%.

[0012] Until recently, the preferred procedure for treating the greatsaphenous vein was surgical stripping. This highly invasive procedureinvolves making a 2.5 cm incision in the groin to expose thesaphenofemoral junction, where the great saphenous vein and its branchesare doubly ligated en masse with a heavy ligature. The distal portion ofthe vein is exposed through a 1 cm incision anterior to the medialmalleolus, and a flat metal or plastic stripper is introduced to exit inthe proximal saphenous vein. The leg is held vertically for 30 secondsto empty the venous tree before stripping the vein from the ankle to thegroin. If the small saphenous vein is also incompetent, it is strippedat the same time from an incision posterior to the lateral malleolus tothe popliteal space. After stripping the veins, the leg is held in thevertical position for three to four minutes to permit vessel ends toretract, constrict, and clot.

[0013] After the stripping procedure, collateral veins are removed bythe avulsion-extraction technique which is illustrated schematically inprior art FIG. 1. By working through small (5 to 8 mm) transverseincisions, segments of vein 10 to 20 cm long can be removed bydissecting subcutaneously along the vein with a hemostat, and thengrasping, avulsing, and removing the vein. With practice, long segmentsof vein in all quadrants can be removed through these small incisions.No attempt is made to ligate the branches or ends of the veins, sincestripping has shown it to be unnecessary. Bleeding is controlled byelevation and pressure for two to four minutes. As many as 40 incisionsare made in severe cases, but their small size and transverse directionpermit closure with a single suture.

[0014] Before closure of the incisions, a rolled towel is rolledrepeatedly from the knee to the ankle and from the knee to the groin toexpress any clots that may have accumulated. The groin incision isapproximated with three 5-0 nylon mattress sutures and all otherincisions are closed with a single suture.

[0015] As can be readily appreciated, the stripping andavulsion-extraction procedures are relatively invasive and requiresignificant anaesthesia. It can therefore be appreciated that it wouldbe desirable to provide an alternative, less invasive procedure whichwould accomplish the same results as stripping and avulsion-extraction.

[0016] Recently, a number of patents have issued disclosing thetreatment of varicose veins with RF energy. Illustrative of these recentpatents are: U.S. Pat. No. 6,200,312 entitled “Expandable Vein LigatorCatheter Having Multiple Electrode Leads”; U.S. Pat. No. 6,179,832entitled “Expandable Catheter Having Two Sets of Electrodes”; U.S. Pat.No. 6,165,172 entitled “Expandable Vein Ligator Catheter and Method ofUse”; U.S. Pat. No. 6,152,899 entitled “Expandable Catheter HavingImproved Electrode Design, and Method for Applying Energy”; U.S. Pat.No. 6,071,277 entitled “Method and Apparatus for Reducing the Size of aHollow Anatomical Structure”; U.S. Pat. No. 6,036,687 entitled “Methodand Apparatus for Treating Venous Insufficiency”; U.S. Pat. No.6,033,398 entitled “Method and Apparatus for Treating VenousInsufficiency Using Directionally Applied Energy”; U.S. Pat. No.6,014,589 entitled “Catheter Having Expandable Electrodes and AdjustableStent”; U.S. Pat. No. 5,810,847 entitled “Method and Apparatus forMinimally Invasive Treatment of Chronic Venous Insufficiency”; U.S. Pat.No. 5,730,136 entitled “Venous Pump Efficiency Test System And Method”;and U.S. Pat. No. 5,609,598 entitled “Method and Apparatus for MinimallyInvasive Treatment of Chronic Venous Insufficiency”. These patentsgenerally disclose a catheter having an electrode tip which isswitchably coupled to a source of RF energy. The catheter is positionedwithin the vein to be treated, and the electrodes on the catheter aremoved toward one side of the vein. RF energy is applied to causelocalized heating and corresponding shrinkage of the adjacent venoustissue. After treating one section of the vein, the catheter can berepositioned to place the electrodes to treat different sections of thevein.

[0017] Although this procedure has gained acceptance and is lessinvasive than the stripping and avulsion-extraction procedures, thereare several disadvantages to it. In particular, RF treatment is actuallyquite slow and painful and the patient must be sufficientlyanaesthetized along the entire length of the veins to be treated. Inaddition, repositioning the catheter is time consuming thus requiringanaesthesia for a prolonged period. Moreover, the RF treatment isincomplete, as only a portion of the vein wall is actually treated, i.e.the portion contacting the electrode. The partially treated vein mayeventually recannularize. Furthermore, tributary veins remain unaffectedand must be treated separately.

SUMMARY OF THE INVENTION

[0018] It is therefore an object of the invention to provide methods andapparatus for the minimally invasive treatment of varicose veins.

[0019] It is also an object of the invention to provide methods andapparatus for the minimally invasive treatment of varicose veins whereinonly minimal anaesthesia is required.

[0020] It is another object of the invention to provide methods andapparatus for the minimally invasive treatment of varicose veins whereintributary veins are treated simultaneously with the vein to which theyconnect.

[0021] It is an additional object of the invention to provide methodsand apparatus for the minimally invasive treatment of varicose veins andconnecting tributaries wherein the entire wall of the vein is evenlysclerosed.

[0022] Another object of the invention is to provide methods andapparatus for the minimally invasive treatment of varicose veins whichdo not utilize high concentration sclerosing agents.

[0023] In accord with these objects which will be discussed in detailbelow, a first embodiment of the present invention includes a catheterhaving three concentric tubes: an innermost tube, an outer tube, and anintermediate tube. The innermost tube has two lumena: a guide wire lumenand an inflation lumen. The distal end of the innermost tube has anatraumatic tip and an integral inflatable occlusion balloon in fluidcommunication with the inflation lumen. The intermediate tube has asingle lumen through which the innermost tube extends. The distal end ofthe intermediate tube has a self-expanding balloon with a plurality offluid pores in fluid communication with the lumen of the intermediatetube. The outer tube has a single lumen through which the intermediatetube extends. The proximal ends of the innermost and intermediate tubesare provided with fluid fittings. The proximal ends of the outer tubeand the intermediate tube are provided with sealing fittings.

[0024] An exemplary treatment method using the first embodiment of theinvention includes elevating the foot above the groin, delivering thecatheter via a guide wire into the saphenous vein from the ankle to thegroin. The patient is then placed in a Trendelenberg position (the bodyinclined downward approximately 30 degrees and the leg elevatedapproximately 60 degrees. The inflatable occlusion balloon is inflatedsufficiently to block blood flow, and moving the outer tube relative tothe intermediate tube (or vice versa) such that the self-expandingballoon expands and contacts the wall of the vein. With the inflatableocclusion balloon securely in place, the intermediate and outer tubesare pulled away from the inflatable occlusion balloon while sclerosingagent is injected into the lumen of the intermediate tube. Thesclerosing agent exits the self-expanding balloon through its pores anddirectly contacts the wall of the vein. Pressure exerted by theself-expanding balloon both massages the wall of the vein and squeegeessclerosing agent evenly into the vein wall. Collateral tributary veinsare injected with sclerosing agent as the self-expanding balloon passesover them. The diameter of the self-expanding balloon becomesprogressively smaller as it is moved from the groin area toward theankle because the diameter of the vein changes accordingly. When theentire vein has been sclerosed, the inflatable occlusion balloon isdeflated and the catheter is removed and the incision is sealed. The legis preferably wrapped with a compression bandage for a few days duringwhich the veins flatten out, thereby removing blood from the vein andallowing the walls of the vein to fuse to itself.

[0025] According to the exemplary treatment using the first embodimentof the catheter, only one small incision is made in the ankle and only asmall amount of anesthetic is required at the place of the incision. Theprocedure is relatively painless. Tributary veins are treatedsimultaneously with the vein into which they feed. The entire wall ofthe vein is evenly sclerosed. Because blood flow is blocked andsclerosing agent is applied directly to the wall of the vein, a lowerconcentration of sclerosing agent can be used as it is not diluted byflowing blood. The occlusion balloon also prevents sclerosing agent fromexiting the treated vein and entering into another vein.

[0026] According to an alternative embodiment, sclerosing agent may beinjected through the lumen of the outer tube. In either case, theself-expanding balloon causes the sclerosing agent to be evenlydistributed and massaged into the wall of the vein.

[0027] A second embodiment of the catheter of the invention has fourtubes, two of which are equipped with inflatable occluding balloons. Theprocedure for using this embodiment involves inflating one balloonupstream and the other downstream and moving the self-expanding balloonbetween them. The two balloons can be inflated to isolate a tributaryfor sclerosing.

[0028] A third embodiment has only one balloon which massages the wallof the vein as sclerosing agent is injected downstream of the balloon.

[0029] A fourth embodiment utilizes a brush having hollow bristles tomassage the wall of the vein as sclerosing agent is injected through thebristles.

[0030] According to the presently preferred embodiments, a drugdispenser attachment is provided to automatically inject the sclerosingagent as the self-expanding balloon is moved through the vein. The drugdispenser, which may or may not be disposable, attaches to a disposablesyringe and includes a rack and pinion gear system for engaging theplunger of the syringe. The gear system is driven by a spool carrying afilament, a ribbon, or a cable. The drug dispenser is attached to thepatient's leg with straps and the end of the cable is attached to theintermediate tube of the catheter such that as the self-expandingballoon is moved through the vein, the cable is pulled causing the spoolto rotate and the rack and pinion gears to engage the plunger of thesyringe and dispense the sclerosing agent. Alternatively, the dispensermay be attached to the catheter and the cable attached to the patient'sleg.

[0031] In addition to treating varicose veins, the methods and apparatuscan be used for the delivery of other intravascular medications such asantiproliferative drugs, for example, Paclitaxel or Rapamycin tocoronary arteries and the like, to prevent restenosis of these vesselsafter stenting. The device can also be used to deliver drugs to otherhollow tubes such as the fallopian tubes or to persistent abnormal sinustracts.

[0032] Additional objects and advantages of the invention will becomeapparent to those skilled in the art upon reference to the detaileddescription taken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a schematic illustration of a prior art technique forthe treatment of varicose veins;

[0034]FIG. 2 is a broken side elevation in partial section illustratinga first embodiment of a catheter according to the invention;

[0035]FIG. 3 is a sectional view taken along line A-A of FIG. 2;

[0036]FIG. 4 is a view similar to FIG. 2 but illustrating the inflatableocclusion balloon inflated inside a vein;

[0037]FIG. 5 is a view similar to FIG. 4 but illustrating theself-expanding balloon expanded inside a vein;

[0038]FIG. 6 is a view similar to FIG. 5 but illustrating theself-expanding balloon after having traversed a portion of the vein;

[0039]FIG. 7 is a view similar to FIG. 6 but illustrating a secondembodiment of the catheter of the invention;

[0040]FIG. 8 is a view similar to FIG. 7 but illustrating a thirdembodiment of the invention;

[0041]FIG. 8a is a view similar to FIG. 8 but illustrating a fourthembodiment of the invention;

[0042]FIG. 8b is an enlarged schematic distal end view of the embodimentof FIG. 8a;

[0043]FIG. 9 is a perspective view of a drug dispenser according to theinvention;

[0044]FIG. 10 is a partially cut away top view of the drug dispenser ofFIG. 9; and

[0045]FIG. 11 is an enlarged perspective view of a winding clutch of thedrug dispenser.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] Referring now to FIGS. 2 and 3, a first embodiment of the presentinvention includes a catheter 10 having three concentric tubes: aninnermost tube 12, an outer tube 14, and an intermediate tube 16. Theinnermost tube 12 has two lumens: a guide wire lumen 18 and an inflationlumen 20. The distal end of the innermost tube includes an atraumatictip 22 and an integral inflatable occlusion balloon 24 in fluidcommunication with the inflation lumen 20. The intermediate tube 16 hasa single lumen 26 through which the innermost tube extends. The distalend of the intermediate tube 16 is provided with a self-expandingballoon 28 with a plurality of fluid pores 30 in fluid communicationwith the lumen 26 of the intermediate tube. The outer tube 14 has asingle lumen 32 through which the intermediate tube 16 extends.

[0047] The proximal end of the innermost tube 12 has a guide wire hub 34which provides access to the guide wire lumen 18 and a fluid port 36 influid communication with the inflation lumen 20. The proximal end of theintermediate tube 16 is provided with a fluid port 38 in fluidcommunication with the lumen 26 and two fittings 40, 42. The fitting 40allows the innermost tube 12 and intermediate tube 16 to be movedrelative to each other while maintaining a seal of the annular fluidspace between the innermost tube 12 and intermediate tube 16. It will beappreciated that the proximal end of the tube 16 can be reinforced withmetal tubing such as thin-walled hypodermic tubing to make it easier topush and provide a more uniform sealing surface. The fitting 42 iseither press fit or glued to the proximal end of the intermediate tube16 or attaches to a luer hub which is press fit or glued to the proximalend of the intermediate tube 16. The proximal end of the outer tube 14has a fitting 44 that seals the space between the outer tube 14 and theintermediate tube 16 and also releasably locks their relative positions.

[0048] An exemplary treatment method using the first embodiment of theinvention can be understood with reference to FIGS. 4-6. Afteranesthetizing the patient's ankle, a guide wire (not shown) is fed intothe saphenous vein V from the ankle to the groin of the patient. Theguide wire can be fed from a cut-down to the vein at the ankle or byusing percutaneous entry techniques well known in the art whichgenerally involves the use of a catheter sheath introducer, and thelike. Once the guide wire is in place, the catheter assembly 10 isthreaded over the guide wire and follows the guide wire up the leg suchthat the tip 22 of the occlusion balloon 24 is located in a desiredlocation, e.g., just proximal to the exit of the saphenous vein in thevicinity of the profunda vein. The exact location of the occlusionballoon can be identified by ultrasound, palpation, or by angiography,and the like. The occlusion balloon 24 is then inflated with a gas orfluid through the port 36. CO₂ gas is the preferred inflator because itis easy to see with ultrasound and it is safely absorbed into the bloodstream should any leakage occur. Once the occlusion balloon 24 isinflated, blood can no longer pass to or from the saphenous vein V viathe profunda vein (not shown).

[0049] With the inflated occlusion balloon in place, as is shown inFIGS. 4 and 5, the fitting 44 of the outermost tube 14 is loosened andthe tube 14 is slid backwards over intermediate tube 16 such that thefitting 44 butts up against connector fitting 42 as shown in FIG. 5.Retracting the outer tube 14 in this manner releases self-expandingballoon 28, which self-expands until it hits the wall of the varicosevein V.

[0050] According to the presently preferred embodiment, theself-expanding balloon 28 is made of a braided mesh, which is braidedsuch that its preferred stable state is fully expanded. The wires of themesh are of a spring material such as stainless steel,cobalt-chrome-nickel (Elgiloy wire), nitinol or the like. Alternatively,the self-expanding balloon wires may be made of a plastic such as PET,PMMA, polyurethane, nylon or the like. The wires may or may not be heathardened to impart greater spring-like properties and memory to themesh. Filling the spaces between the braid wires is a thin membrane 49made from an elastomeric material such as polyurethane, silicone rubber,polyolefin, polyamide copolymers and the like. The membrane can beformed by dip molding, insert molding or it can be formed separately andglued in place. Those skilled in the art will appreciate that theself-expanding balloon both shortens in length and widens in diameter asit achieves its preferred expanded state. It will be appreciated thatthe distal end of the balloon 28 is dimensioned such that it can moveover the inner tube 12 but still maintain a fluid seal between theballoon 28 and the tube 12. As illustrated in FIGS. 4-6, a plurality offluid pores 30 in the membrane 49 are located about the circumference ofthe balloon 28.

[0051] When the catheter 10 is in the position shown in FIG. 5, a sourceof sclerosing agent (or a microfoam containing a sclerosing agent) iscoupled to the port 38 and operated to allow sclerosing agent to flowthrough the annular space between the tubes 12 and 16, into the balloon28 and out through the pores 30. It will be appreciated that sclerosingagent so dispensed with flow directly into the wall of the vein V.According to the invention, as sclerosing agent is being dispensed, theself-expanding balloon 28 is moved away from the balloon 24 as shown inFIG. 6 by moving the tubes 14 and 16 relative to the tube 12. It will beappreciated that as the balloon 28 is moved along the length of thetapering vein V, the balloon decreases in diameter and lengthens. Thesclerosing agent exiting the pores 30 is massaged or “squeegeed” intothe wall of the vein V by means of the outward pressure exerted by theballoon 28 against the wall of the vessel V.

[0052]FIG. 6 shows the occlusion balloon 24 remaining in place as theself-expanding balloon 28 has traversed along a length of the vessel V.Sclerosing agent is continually injected through the balloon 28 as it iswithdrawn. It can also be appreciated that as the balloon 28 passescollateral (tributary) veins such as those identified as T1 and T2,sclerosing agent fills the collateral veins to effectively cause them tosclerose. It will be appreciated that additional sclerosing agent can beinjected into the tributary veins by means of a second syringe fluidlycoupled to the inlet port 38 by means of a T-connector

[0053] According to the presently preferred embodiment, the balloon 28is withdrawn through the entire length of the vein V to be sclerosed.When the entire length is traversed, the occlusion balloon 24 isdeflated, the catheter 10 is removed and the puncture site is sealed.Simultaneous with the removal of the occlusion balloon, or just prior todeflation of the balloon, or even during the procedure, the leg of thepatient is preferably wrapped with an elastic compression bandage, e.g,an ACE BANDAGE, with other compression objects such as foam, etc..Wrapping the leg in this manner causes the vein to flatten-out, therebyremoving blood from the vein and allowing the lumen to fuse to itself inthe collapsed embodiment. After a few days of compression the bandagesare removed and the vein is no longer medically or cosmeticallyproblematic.

[0054] It has been discovered that, due to the “squeegee-like” action ofthe self-expanding balloon 28, the sclerosing agent need not bedispensed at the outer circumference of the balloon. Thus, the pores 30of the balloon may be located on the proximal portion of the balloon.Alternatively, the balloon need not have any pores, but pores may beprovided at the distal end of the tube 16. As yet another alternative,neither the balloon nor the intermediate tube are provided with pores,but the sclerosing agent is provided via the outer tube 14. In allcases, the sclerosing agent will flow or be forced toward the wall ofthe vein and be massaged into the vein wall by the balloon 28.

[0055] Those skilled in the art will appreciate that if the sclerosingagent is not injected through the balloon 28, the balloon need not beself-expanding. It could be an inflatable balloon which is inflated witha gas or a saline solution from an IV bag, etc. In this embodiment, thepressure can be adjusted as the balloon traverses the vein and thediameter of the vein changes.

[0056] As mentioned above, the catheter of the invention can be used todeliver other types of intravascular medication directly to the wall ofa vein. Although the treatment of varicose veins generally involvestreating the entire length of the vein, other treatments may require orprefer that only a selected portion of the blood vessel be treated.Accordingly, a second embodiment of the invention is illustrated in FIG.7 in which two inflatable occlusion balloons are provided to isolate aregion of a blood vessel for treatment.

[0057] As shown in FIG. 7, the catheter 110 has four tubes: an innermosttube 112, an outer tube 114, and two intermediate tubes 116 and 117. Theinnermost tube 112 has an inflatable balloon 124 with an atraumatic tip122 at its distal end. The innermost tube 112 is substantially the sameas the tube 12 described above. The outer tube 114 and intermediate tube116 are also substantially the same as the tubes 14 and 16 describedabove. The additional tube 117 resides in the annular space between thetubes 114 and 116. It has an inflatable balloon 125 at its distal endand is similar to the tube 112 in that it has two lumen, one of whichcarries the tube 116 and the other of which is used to inflate theballoon 125. The procedure for using this embodiment involves inflatingone balloon upstream and the other downstream and moving theself-expanding balloon between them while injecting an intravasculardrug. This allows treatment of a selected portion of a blood vesselwithout diluting the treatment drug. It will also be appreciated thatthe catheter 110 can also be used to isolate one or a plurality oftributary veins by inflating the balloons on opposite sides of thetributary or tributaries. Sclerosing agent is then injected between theballoons and forced into the tributary or tributaries,

[0058] A third embodiment of a catheter 210 according to the inventionis shown in FIG. 8. This embodiment includes an outer tube 214 and aninner tube 216. The distal end of the inner tube 216 is provided with aself-expanding balloon 228. According to this embodiment, the balloon228 is optionally provided with an abrasive surface 231 and/or pores(not shown). When an abrasive surface is provided, the catheter 210 maybe used with or without a sclerosing agent. In these instances,treatment may consist of abrading the wall of the blood vessel with theabrasive surface 231 of the balloon 228. In other instances, where poresare provided in the balloon, treatment may consist of abrading the wallof the vain (if the balloon has an abrasive surface) as the sclerosingagent is injected out of the pores. In yet other instances, when nopores are provided in the balloon, treatment may include injecting anintravascular drug through the annular space between the outer tube 214and the inner tube 216 or through pores (not shown) at the distal end ofthe inner tube 216. If the balloon 228 is moved against the flow of thedrug (from right to left as seen in FIG. 8), the drug will be massagedinto the wall of the blood vessel (which is abraded if the balloon hasan abrasive surface) by the balloon 228.

[0059] A fourth embodiment of a catheter 410 according to the inventionis shown in FIGS. 8a and 8 b. This embodiment includes an outer tube 414and an inner tube 416. The distal end of the inner tube 416 is providedwith a brush 430 having a plurality of hollow bristles, e.g. 430 a-430 pand a plug 418. The hollow bristles are in fluid communication with theinner tube 416 such that a sclerosing agent may be injected through thetube 416 and exit the ends of the bristles. The bristles 430 a-430 p arepreferably made of a resilient material so that they will expand to theposition shown in the Figures, i.e., approximately radial to the innertube, when released from the outer tube. A method for using the fourthembodiment includes moving the outer tube and/or inner tube until thebristles 430 a-430 p are collapsed inside the outer tube, delivering thetwo tubes to a procedural site in a blood vessel, moving the outer tubeand/or inner tube until the bristles 430 a-430 p are expanded as shownin the figures, then moving the inner tube relative to the blood vesselwhile injecting a sclerosing agent through the inner tube and thebristles.

[0060] According to the presently preferred embodiments, a drugdispenser attachment is provided to automatically inject the sclerosingagent as the self-expanding balloon is moved through the vein. FIG. 9shows a three dimensional view of a drug dispenser 300 with a body 302defining a channel for receiving a disposable syringe 304, an injectorcam 306, a string 308 with a hook 309, a winding clutch 310 (shown infurther detail in FIG. 11) and slots 312.

[0061]FIG. 10 is a partially cut away top view of the dispenser 300. Asshown in FIG. 10, the string 308 with hook 309 is wound on spool 314.The spool 314 is rigidly attached to the winding clutch 310 andclutchingly attached to an axle 316. The axle 316 is rigidly attached toa spur gear 318. The spur gear 318 engages a second spur gear 320, whichin turn is rigidly attached to an axle 322 which carries a pinion gear324. The pinion gear 324 engages a rack 326, which is attached to theinjector cam 306. As seen in FIG. 10, the injector cam 306 is alignedwith the plunger 305 of the disposable syringe 304.

[0062] As seen in FIG. 11, the winding clutch 310 includes a clutchhousing 328 and a cam 330. The clutch housing 328 defines a center hole332 through which the axle (316 in FIG. 10) extends. The cam 330 definesa hole 334 with an adjacent keyway 336. The cam 330 is spring biased bya spring 338 so that the keyway 336 aligns with the hole 332 and engagesflats (not shown) which are machined on the axle (316 in FIG. 10). Whenthe cam 330 is pressed at 340, the hole 334 lines up with the hole 332and the flats on the axle are no longer engaged causing clutch 310 torotate without engaging the axle and without dispensing sclerosing agentfrom syringe 304. This feature allows the string 305 to be wound ontothe spool 314. It also provides the surgeon with a mechanism to lengthenor shorten the string without dispensing sclerosing agent from thesyringe.

[0063] The drug dispenser 300 works as follows. The body 302, with theexit of the syringe 304 pointed towards the patient's foot, is fastenedto the patient's leg, preferably adjacent the ankle, via straps such asVELCRO straps which are fed through the slots 312. The sclerosingcatheter (e.g. 10 in FIG. 2) is maneuvered into the patient's vein froma puncture site in the patient's ankle. The proximal hub 42 (FIG. 2) ofthe sclerosing catheter is attached to the hook 309 at the end of thestring 308. As the sclerosing catheter is pulled out of the vein,tension on string 308 causes pulley 314 to rotate which causes thepinion 324 to rotate (via gears 318 and 320) and rack 326 to move. Thecam 306 on the rack 326 presses the plunger 305 causing sclerosing agentto be discharged from syringe 304. Those skilled in the art willappreciate that a fluid conduit may be required to couple the fluid exitof the syringe 304 to the fluid port 38 (FIGS. 2, 4, and 5). It willalso be appreciated that the gear ratios of the drug dispenser can beselected such that the appropriate volume of sclerosing agent dispensesas the catheter is pulled out of the leg. The main purpose of theinjector is to allow the physician to dispense a continuous amount ofsclerosing agent into the patient as a function of the withdrawal of thecatheter. It can be appreciated that no sclerosing agent is dischargedif the catheter is not pulled and that the flow rate of sclerosing agenttracks the speed at which the catheter is withdrawn. As mentioned above,the drug dispenser can be used in conjunction with one of the cathetersto dispense other kinds of intravascular drugs for different procedures.

[0064] Those skilled in the art will appreciate that the drug dispensermay be attached to the catheter and the string attached to the patient'sleg. Moreover, it will be appreciated that the clutch may be omitted ifan adjustable length cable is used. It will also be appreciated thatother types of clutches could be used at any of the gears or axles.

[0065] There have been described and illustrated herein severalembodiments of methods and apparatus for sclerosing the wall of avaricose vein. While particular embodiments of the invention have beendescribed, it is not intended that the invention be limited thereto, asit is intended that the invention be as broad in scope as the art willallow and that the specification be read likewise. For example, thecatheter can be provided with an integral guide wire and the catheterand the guide wire can be inserted simultaneously. Also, the dual lumencatheter can be formed by two concentric tubes with the inflation lumenbeing the annular space between the tubes. It will therefore beappreciated by those skilled in the art that yet other modificationscould be made to the provided invention without deviating from itsspirit and scope as so claimed.

1. An apparatus for delivering an intravascular drug, said apparatuscomprising: a) a first catheter tube having a proximal end, a distalend, and a fluid lumen extending from its proximal end to its distalend; b) an inflatable balloon coupled to said distal end of said firstcatheter and in fluid communication with said fluid lumen; c) a secondcatheter tube having a proximal end, a distal end, and a lumen extendingfrom its proximal end to its distal end, said first catheter tubeextending through said lumen of said second catheter tube; d) aself-expanding balloon coupled to said distal end of said secondcatheter tube, said first catheter tube extending through saidself-expanding balloon; and e) a third catheter tube having a proximalend, a distal end, and a lumen extending from its proximal end to itsdistal end, said second catheter tube extending through said lumen ofsaid third catheter tube, wherein at least one of said second cathetertube and said third catheter tube is adapted to receive and deliver theintravascular drug to the location of said self-expanding balloon.
 2. Anapparatus according to claim 1, wherein: said first catheter tube has aguide wire lumen extending from its proximal end to its distal end. 3.An apparatus according to claim 1, wherein: said second catheter tube isadapted to receive and deliver the intravascular drug, and saidself-expanding balloon includes a plurality of fluid pores, said fluidpores being in fluid communication with said lumen of said secondcatheter tube.
 4. An apparatus according to claim 1, wherein: saidsecond catheter tube is adapted to receive and deliver the intravasculardrug, and said distal end of said lumen of said second catheter tube hasa plurality of fluid pores.
 5. An apparatus according to claim 1,wherein: said third catheter tube is adapted to receive and deliver theintravascular drug.
 6. An apparatus according to claim 1, wherein: saidthird catheter tube has a proximal locking means for locking thelocation of said second catheter tube relative to said third cathetertube.
 7. An apparatus according to claim 1, wherein: said first cathetertube is adapted to receive the intravascular drug by having a proximalport in fluid communication with said fluid lumen of said first cathetertube.
 8. An apparatus according to claim 1, wherein: said secondcatheter tube is adapted to receive the intravascular drug by having aproximal port at said proximal end of said second catheter tube in fluidcommunication with said fluid lumen of said second catheter tube.
 9. Anapparatus according to claim 1, further comprising: f) a fourth cathetertube having a proximal end, a distal end, and a lumen extending from itsproximal end to its distal end, said third catheter tube extendingthrough said lumen of said fourth catheter tube; and g) a secondinflatable balloon coupled to the distal end of said fourth catheter.10. An apparatus according to claim 1, further comprising: f) a drugdispenser having a drug reservoir and a drug outlet, said drug outletbeing fluidly coupled to said fluid delivery means, said drug dispenserbeing adapted to automatically dispense the drug from the reservoir intothe fluid delivery means as said second catheter tube is moved through ablood vessel.
 11. An apparatus according to claim 10, wherein: said drugreservoir is a syringe having a plunger, and said drug dispenserincludes means for moving said plunger as said second catheter tube ismoved through a blood vessel.
 12. An apparatus according to claim 11,wherein: said means for moving said plunger includes a gear coupled tosaid plunger, a spool coupled to said gear, and a filament, ribbon, orcable coupled to said spool.
 13. An apparatus according to claim 10,wherein: said drug dispenser includes means for coupling said drugreservoir to a patient's limb.
 14. An apparatus according to claim 10,wherein: said drug dispenser includes means for coupling said drugreservoir to one of said catheter tubes.
 15. An apparatus for deliveringan intravascular drug, said apparatus comprising: a) a catheter having aproximal end, a distal end, and a lumen extending from its proximal endto its distal end; b) a drug reservoir having a drug outlet, said drugoutlet being fluidly coupled to the proximal end of the lumen of thecatheter, c) dispensing means coupled to said drug reservoir, saiddispensing means being adapted to automatically dispense the drug fromthe reservoir into the lumen of the catheter as the catheter is movedthrough a blood vessel.
 16. An apparatus according to claim 15, wherein:said drug reservoir is a syringe having a plunger, and said dispensingmeans includes means for moving said plunger as said catheter is movedthrough a blood vessel.
 17. An apparatus according to claim 16, wherein:said means for moving said plunger includes a gear coupled to saidplunger, a spool coupled to said gear, and a filament or cable coupledto said spool.
 18. An apparatus according to claim 15, furthercomprising: d) attachment means for attaching said drug reservoir to apatient's limb.
 19. An apparatus according to claim 15, furthercomprising: d) attachment means for attaching said drug reservoir tosaid catheter.
 20. An apparatus for delivering an intravascular drug,said apparatus comprising: a) a first catheter tube having a proximalend, a distal end, and a lumen extending from its proximal end to itsdistal end; b) a self-expanding balloon coupled to said distal end ofsaid first catheter tube; and c) a second catheter tube having aproximal end, a distal end, and a lumen extending from its proximal endto its distal end, said first catheter tube extending through said lumenof said second catheter tube, wherein at least one of said firstcatheter tube and said self-expanding balloon includes pores, and saidfirst catheter tube is adapted to receive and deliver the intravasculardrug to said pores.
 21. An apparatus according to claim 20, wherein:said self-expanding balloon is comprised of spring wires and a thinmembrane coupled to said spring wires.
 22. An apparatus according toclaim 20, wherein: said self-expanding balloon includes an abrasiveouter surface.
 23. An apparatus according to claim 20, wherein: saidself-expanding balloon is made of plastic.
 24. An intravascularapparatus, comprising: a) a first catheter tube having a proximal end, adistal end, and a lumen extending from its proximal end to its distalend; b) a self-expanding balloon coupled to said distal end of saidsecond catheter tube and having an abrasive outer surface; and c) asecond catheter tube having a proximal end, a distal end, and a lumenextending from its proximal end to its distal end, said first cathetertube extending through said lumen of said second catheter tube.
 25. Anintravascular apparatus according to claim 24, wherein: at least one ofsaid first catheter tube and said self-expanding balloon includes pores,and said first catheter tube is adapted to receive and deliver anintravascular drug to said pores.
 26. A method for treating a varicosevein, comprising: a) delivering a first catheter having a ballooncoupled at a distal end thereof through an incision and up the varicosevein; b) expanding the balloon; and c) dispensing a sclerosing agentadjacent the balloon.
 27. A method according to claim 26, furthercomprising: d) partially removing the catheter from the varicose veinvia the incision with the balloon expanded while continuing saiddispensing of said sclerosing agent.
 28. A method according to claim 26,further comprising: providing a second catheter over said first catheterand over said balloon, wherein said balloon is a self-expanding balloon,and said expanding comprises withdrawing said second catheter from oversaid self-expanding balloon.
 29. A method according to claim 28,wherein: said dispensing comprises dispensing said sclerosing agent viasaid second catheter.
 30. A method of delivering an intravascular drugto a blood vessel, said method comprising: a) delivering a firstcatheter via an incision to a first location in the blood vessel; b)dispensing the intravascular drug through the first catheter whilemoving the first catheter from the first location to a second locationas the first catheter is at least partially pulled out of the incision;and c) removing the first catheter from the blood vessel.
 31. A methodaccording to claim 30, wherein: said delivering a first catheter to afirst location includes delivering said first catheter and a secondcatheter having a balloon at a distal end thereof to the first location,said second catheter extending through said first catheter, andinflating the balloon.
 32. A method according to claim 30, wherein: saidfirst catheter has a self-expanding balloon coupled to a distal endthereof, and said dispensing includes dispensing the drug adjacent theself-expanding balloon.
 33. A method according to claim 32, wherein: atleast one of said catheter and said self-expanding balloon includepores, and said dispensing includes dispensing the drug through saidpores.
 34. A method according to claim 32, wherein: said delivering afirst catheter to a first location includes delivering said firstcatheter and a second catheter to said first location, said secondcatheter extending over said first catheter and said self-expandingballoon, said method further comprising withdrawing said second catheterfrom over said self-expanding balloon, wherein said dispensing includesdispensing the drug through said second catheter.
 35. A method ofdelivering an intravascular drug to a blood vessel, said methodcomprising: a) delivering a catheter system via an incision to a firstlocation in the blood vessel, said catheter system having first, second,and third catheter tubes with first, second, and third balloons coupledto respective distal ends thereof, said second balloon being aself-expanding balloon, said third catheter tube extending through saidsecond catheter tube, and said second catheter tube extending throughsaid first catheter tube; b) inflating said third balloon at said firstlocation; c) causing said self-expanding balloon to expand; d) inflatingsaid first balloon at a second location; e) dispensing the drug throughthe second catheter tube; and f) moving said second catheter with saidsecond balloon so that said second balloon moves between said firstlocation and said second location.
 36. A kit for the intravasculartreatment of a blood vessel, said kit comprising: a) a catheter havingan expandable balloon at its distal end and a drug delivery lumen; andb) a drug dispenser having a drug reservoir fluidly coupled to said drugdelivery lumen, wherein said drug dispenser includes means forautomatically dispensing a drug from said drug reservoir into said drugdelivery lumen in response to movement of said catheter through theblood vessel.
 37. A kit according to claim 36, wherein: said drugreservoir includes a syringe having a plunger and said means forautomatically dispensing includes means for depressing said plunger. 38.An apparatus for delivering an intravascular drug, said apparatuscomprising: a) a first catheter tube having a proximal end, a distalend, and a first lumen extending from its proximal end to its distalend; b) a first inflatable balloon coupled to said distal end of saidfirst catheter and in fluid communication with said first lumen; c) asecond catheter tube having a proximal end, a distal end, and a secondlumen extending from its proximal end to its distal end, said firstcatheter tube extending through said second lumen; d) a secondinflatable balloon coupled to said distal end of said second cathetertube and in fluid communication with said second lumen; and e) a thirdcatheter tube having a proximal end, a distal end, and a third lumenextending from its proximal end to its distal end, said second cathetertube extending through said third lumen, wherein said third lumen isadapted to receive and deliver the intravascular drug to the location ofsaid second inflatable balloon.
 39. An apparatus for delivering anintravascular drug, said apparatus comprising: a) a first catheter tubehaving a proximal end, a distal end, and a lumen extending from itsproximal end to its distal end; and b) a brush having a plurality ofhollow bristles coupled to said distal end of said first catheter tubeand being in fluid communication with said lumen, wherein said firstcatheter tube includes means for injecting a vascular drug into saidlumen such that the drug exits through said hollow bristles of saidbrush.
 40. An apparatus according to claim 39, further comprising: c) asecond catheter tube having a proximal end, a distal end, and a lumenextending from its proximal end to its distal end, said first cathetertube extending through said lumen of said second catheter tube.